DUBLIN, Sept 1 (Reuters) - Ireland coach Joe Schmidt named just two recognised scrumhalves in his World Cup squad on Tuesday and will rely on flyhalf Ian Madigan as emergency cover to allow Darren Cave travel as specialist backup at centre.

The Six Nations champions have no fresh injury concerns ahead of their first game against Canada on Sept. 19 and included prop Cian Healy, currently recovering from injury, in a full strength 31-man panel loaded with depth.

Winger Andrew Trimble, Ireland's breakout performer in their first of two successive Six Nations triumphs in 2014, missed out in the most competitive spot after playing just 34 minutes of rugby in the last eight months.

While some coaches have opted to bring two hookers, Schmidt followed Australia's Michael Cheika in gambling at scrumhalf. However, unlike Matt Giteau who has played there for the Wallabies, Madigan has little experience at number nine.

Schmidt said last week that Madigan had not trained at scrumhalf with Ireland, but did recall the slick passer training there during the Kiwi coach's time in charge of Leinster.

"There were some very tight decisions, particularly in the back three and it was also a challenge to make sure that key positions were covered as much as a squad of 31 players allows," Schmidt said in a statement.

"A number of players were very unlucky to miss selection."

Competition was so intense in the back three that only fullback Rob Kearney was a sure selection with Tommy Bowe, Ireland's third highest try scorer of all time, not certain of a place until Schmidt named the squad of 17 forwards and 14 backs.

The in-form Dave Kearney and Simon Zebo were the other out-an-out wingers included -- with Munster's Zebo also providing cover at fullback -- while the versatile Keith Earls and Luke Fitzgerald will also be pushing for a start.

In the pack, backup tighthead props Nathan White and Tadhg Furlong, who have just three caps between them, beat Marty Moore in another tight call after injury kept Moore out of the recent warm-up games.

Paul O'Connell will captain the squad that will also face Romania, Italy and France as Ireland seek to progress beyond the quarter finals of a World Cup for the first time.